Lewis Hamilton is hoping to overtake Nico Rosberg off the line, otherwise says he may have to wait until the pit stops to take the lead in Spain.
Hamilton's pole position run came to an end at the Barcelona circuit on Saturday where Rosberg beat him by 0.267s.
"I did not have the pace today," Hamilton admitted after finishing second.
"Nico did a great job and generally I don't think I had the balance where I like it.
"But I did my best with it and tomorrow there's a lot to play for."
And the most important is the victory.
As yet Rosberg has not beaten Hamilton on a grand prix Sunday this season while the Brit has won three of the four races.
It won't be easy to add a fourth this Sunday as the Barcelona circuit is notoriously difficult to overtake on.
Hamilton, though, says he'll try it either at the start or through the pit stops.
"Hopefully, yeah, it is always one of the opportunities," he said when asked about the start.
"You have that [the start] and some of the pit stops. It is very, very difficult to overtake here."